1. Field of the Invention.
The present invention relates generally to cutting units and more particularly to a hair trimmer.
2. Description of the Prior Art.
There are numerous cutting units known in the art. One type of unit utilizes a reciprocating tooth blade moving relative to a second blade. The blades are aligned substantially longitudinally of the device and its handle. When this arrangement is utilized in a hair trimmer, the device can be conveniently used by an untrained individual because the orientation of the blades is similar to that of a comb. Using blades with a curved cutting edge further facilitates trimming and proper shaping of the hair.
Disadvantageously, as is known in the art, see e.g. U.S. Pat. No. 4,214,365 to Walter, et al., when these reciprocating cutting units have a high motor and blade speed the noise is a deterrent to its use. When low motor and blade speeds are utilized, the motor noise factor may be reduced, but the sickle bar or mowing-machine noise of the blade remains, particularly if the blade is long.
These units also have relatively high costs and complex constructions which make assembly, repair and cleaning difficult. A major factor in the cost is the fabrication of a long moveable cutting blade. The dimensions of a long, moveable blade require exactitude in fabrication since improper frictional contact with the second blade is capable of producing a substantial noise when reciprocated and increased wear and tear on cutting components. A curvature in a long cutting blade further increases its cost. Prior art reciprocating cutting units have not been entirely satisfactory, with respect to noise, maintainability and cost.
It is, accordingly, an object of the present invention to provide an easily manipulated, efficient, quiet, hair trimmer having relatively few components that is particularly well-adapted for self-use.
It is an additional object of the present invention to provide a hair trimmer which can be drawn through a bed of hair in a combing motion while shearing off hair segments.
It is a further object of the present invention to provide a hair trimmer having a cutting unit with multiple aligned curvate cutting blades which are coupled for simultaneous reciprocation.
It is also an object of the present invention to provide a hair trimmer having multiple cutting blades which are aligned to form a curvature in their cutting edges approximating the curvature of the human head.